CD2 Lozenges in Preventing Acute Oral Mucositis in Patients With Head and Neck Cancer Receiving Radiotherapy and Chemotherapy

DISEASE CHARACTERISTICS: * Histologic proof of squamous cell carcinoma of the oral cavity, oropharynx, nasopharynx, hypopharynx, or larynx * Planned course of definitive or post-operative radiotherapy (RT) to a total dose of ≥ 60 Gy using 1.8 to 2.0 Gy per fraction * At least one third of the oral cavity mucosa must be included in the RT fields, as estimated by the treating radiation oncologist * Planned concurrent administration of cisplatin chemotherapy (either 100 mg/m\^2 every 3 weeks or 30-40 mg/m\^2 every week) PATIENT CHARACTERISTICS: * ECOG performance status (PS) 0, 1, or 2 * Hemoglobin ≥ 10.0 g/dL * White blood cell (WBC) ≥ 3,500 x10\^9/L * Absolute neutrophil count (ANC) ≥ 1,500 x10\^9/L * Platelet count ≥ 100,000 x10\^9/L * Willing to abstain from ingestion of yogurt products and/or any product containing probiotics during study drug treatment * Ability to complete questionnaire(s) by themselves or with assistance * Willing to provide saliva samples for correlative research purposes (first 50 patients) * Not pregnant or nursing * Negative pregnancy test done ≤ 7 days prior to registration, for women of childbearing potential * Men or women of childbearing potential must employ adequate contraception * No co-morbid systemic illnesses or other severe concurrent disease which, in the judgment of the investigator, would make the patient inappropriate for entry into this study or interfere significantly with the proper assessment of safety and toxicity of the prescr…